Liquid coating compositions



smote 10.1060

LIQUID COATING COMPOSITIONS Edward L. Krona. Old Greenwich, and George W.

Ila-low, Stamford, Coma. assignors to American Cyanamid Company. New York. N. Y., a

corporation of Maine No Drawing. Application July 24, 1048. Serial No. 40,629

I 'lhis invention relates to liquid coating compositions and more particularly to flat (dull. matte) liquid coating compositions containing an organic 8am iflatteniml agent; Specifically the invention is concerned with list liquid coating compositions comprising a film-forming liquid and a ilnely divided (produced. for example. by grindingl acrylonitrile polymerisation product containing at least 85% by weight thereof of combined acrylonitrile and which is substantially insoluble in the iilm-iorming liq id. The polymeric or copolymeric acrylonitriie is an adjuvant for varnishes. lacquers. enamels and the like. and serves to dull the appearance coatings obtained therefrom.

l'br many purposes it is desirable to coat suriaces with a protective and decorative ilnish which is more or less list or dull instead oi the more common. highly glossy nnish. Examples of such applications are in the finishing of furniture and the painting of equipment for the milltary-tomes where a non-reflecting surface is de-- Various gloss-reducing or flatting agents. both organic and inorganic. heretofore have been used or suggested as adiuvants in him-forming liquids in order to obtain a dry coating with the desired flat ilnish. Such adiuvanis have included inorganic netting agents. e. g.. magnesia. magnesium carbonate, diatomaceous earth. asbestine and amorphous 'slli'ca, the disadvantages of which are pointed out in. for instance. Laus Patent No. 2,398,051. Insoluble metallic soaps also have been employed as flatting agents. e. g.. aluminum. magnesium and nine stearates. the disadvantages of which'are discussed in. for example. Miles Patent No. 2,214,771. Other adjuvants which have been used or suggested for use as'i'iatting agents in himlorming liquids include the zinc, magnesium, alumlnum and calcium soaps oi oiticica oil acids (see Patent No. 2.214.771, supra); silica gels having an alcohol as at least the major portion oi the liquid or continuous phase. which gels also are known as-"siiica-alcogels" (see Healy Patent No. 2.377340% certain organogels of an inorganic oxide. such as anoxide oisillcon. aluminum, magnesium. titanium. thorium. chromium. iron and nickel. and wherein an organic solvent. e. g., acetone. alcohol. etc.. constitutes at least the molar portion of the liquid or mntinuous phase (see Patent No. 2.396.051. supra): aerogels, speciflcally silica aerogels. which are formed by rethe continuous phase of a gel under such conditions that the surface tension oi the liquid continuous phase isnero or very small (see Hari'ordlfatent N9. 2.180.145); and organic iiattins agents oi the in'etal type (see 'Auer ?atenis 2,418,450 and 2,433,833. the specifications of 1G (llailns. (Cl. 200-17) which also contain a rather complete discussion of methods of flattening liquid coating compositions and of the various kinds of flatting agents commonly used to secure this result).

The present invention is based on our discovery that alcrylonitrile polymerization products of the kind described briefly in the first paragraph of this specification and more fully hereafter have particular and peculiar pr p rties which render them eminently suitable for use as a flatting agent in a film-forming liquid material. that is. in a liquid material containing or comprising a base which. upon baking, drying or other operation, yields or is converted into a solid illm upon the surface of the object to which the liquid flimtorming or coating composition has been applied. For example, the acrylonitrile polymerization products are inert to attack by most chemicals, are unailected by water. are substantially insoluble in the usual solvents employed in liquid coating compositions, and have a relatively low density. In view of their low density they can be used in smaller quantities thanmany oi the conventional iiatti-ng agents and still obtain 'the'desired ilatting eflect.

Polymeric and copolymeric acrylonitriles have still other properties which make them especially suitable for use as flatting agents in paints. varnishes, lacquers. enamels and other fllm-iorming liquid coating compositions. For instance. the matter of obtaining satisfactory flatting of a coating composition comprising a catalyzed blend of alkyd and urea-formaldehyde resins has been a considerable problem in the past, and it has been necessary to avoid the use of many flatting agents in such compositions either because of their tendency to absorb the catalyst or to reduce the cure rate or because of their reactivity. In coating compositions of this kind. these diihculties are obviated by using an alcrylonitrile polymerization product. More particularly we have found that in such compositions polymeric acrylonitrile was superior to all other conventional iiatting agents which were tested. including the metallic soaps. For example. the metallic stearates" prevented satisiactory curing of the resin illm. as did also the aluminum soap 0! an adduct 01 maleic acid and rosin.

Since many dulled finishes are given a rubbing treatment alter application to a surface. e. g.. a desk top. it is necessary taht a bloom-free illm be produced after rubbing. Acrylonitrile polymerisation products, when incorporated into coatim compositions as a netting agent. impart to such compositions the ability to pass thbtest satciactorily. Thus. flat liquid coating compositions containing polymeric or copolymeric mama-us yield a brilliant. clear illm after rubbing whereas unsatisfactory gray films result when other flatting agents, e. g., aluminum stearate, diatomaceous earth, etc., are used in a liquid coating composition which otherwise is the same.

Unlike some of the conventional flatting agents, e. g., the stearates, the acrylonitrile polymerization products used in practicing our invention do not degrade the toughness of the dried or baked illm and may actually reinforce the film. Furthermore. the water resistance of films containing a small amount of a polymer or copolymer of acrylonitrile as a flatting agent is markedly superior to that of similar films containing other flatting agents, e. g., silica gel, magnesium carbonate, etc.

The remarkable fiatting characteristics of acrylonitrile polymerization products can be utilized to advantage in pigmented paints and enamels. In such coating compositions the addition of a relatively small amount of polymeric or copolymeric acrylonitrlle can be used to replace a lar er amount of pigment. e. g., titanium dioxide,

and still obtain the same d ree of flatness as with the pigment alone: or. the flatness of a lowly pigmented paint or enamel can be improved by incorporating therein a small amount of an acrylonltriie polymerization product.

The polymeric and copolvmeric acrylonitriles used in practicing our invention generally show little or no tendency to settle from film-forming liquid materials to which they have been added:

'or. if they do show any tendencv to settle, they settle slowly to a soft. easily redls ersib e sediment. This is in marked contrast to that of many of the conventional flatting a ents. e. g., silica gel. which. after it has settled. tends to pack to a dense mass. The ability of the acrvlonitrile pol merization products to form a relatively stable sus ens on in llouid film-forming materia s in which they have been dis ersed. the volume loading which their low den ity permits and the aforementioned desirable characteristics constitute an unlnue and unobvious comb nation of properties which renders these polymeric materials eminently suitable for use as fiatting agents in a nts. varnishes. enamels. lacquers and other iinuid film-formin materials or compositions including those of the oleoresinous type or kind.

Polymeric acrvlonitri e and acrvlonitrile copolymers contain ng at least 85% by wei ht thereof of combined acry onitrile. that is. acrylonitrile polymerization products conta nin in the polymer molecules an avera e of at least 85% by wei ht of acrylonitrile. and which are substantiallv inso uble in the liouid component or vehicle of the film-forming liouids in which they are incorporat d. are em lo ed in practicing our invention. The acrvlonitri e polvmers and co olymers are re ared by methods now well known to those skilled in the art. In the case of conolvmers, the polymerizat on rates of the individual monomers in a polymerizable mixture may be different. with the result that the pro ortions oi the components in the final copolymer are different from the pro ortions thereof in the mixture of monomers which is polymerized. In preparing acrylonitrile copolvrners which are used in carrying our invention into effect. the pro ortions of monomers in the polymerizable mixture from which the copolymer is made preferably are adjusted so that the final co olmer contains in the molecules thereof an average of at least 85% by weight of acrylonitrlle. that is. the acrylonitrile polymerization product contains at least 85% by weight thereof of combined acrylonitrile. By the expressions "polymerization product containing in the polymer molecules an average of at least by weight of acrylonitrile and acrylonitrile polymerization product containing at least 85% by weight thereof of combined acrylonitrile" as used herein and/or in the appended claims are meant a polymerization product (polymer. copolymer or interpolymer or mixture thereof) containing in its molecules an average of at least 85% by weight of the acrylonitrile unit, which is considered to be present in the individual polymer molecule as the group or, otherwise stat d. at'l ast 85% by weight of the reactant substance converted into and forming the polymerization product is acrylonitrile (combined acrylonitrile).

Illustrative examples of monomers which may be copolymerized with acrylonitrile to yield a polymerization product (copolymer or interpolymer) containing an average of at least 85% by weight of acrylonitrile are the un aturated alcohol esters, more particularly the ally], metallyl, crotyl, l-chloroallyl, 2-chloroallyl, cinnamyl, vinyl, methvinyl. l-phenylallyl, butenyl, propargyl, butynyl, etc., esters of saturated and unsaturated, aliphatic and aromatic, monobasic and polybasic acids such, for instance. as acetic, propionic, butyric, valeric, caproic, acrylic and alpha-substituted acrylic (including alkacrylic. e. g., methacrylic, ethacrylic, propacrylic, etc.. and arylacrylic, e. g., phenylacrylic. etc), crotonic, oxalic. malonic, succinic, glutaric, adipic. pimelic, suberic, azelaic, sebacic, maleic, iumaric. citraconic, mesaconic. itaconic, aconitic, benzoic, phenylacetic, phthalic, terephthalic, benzoylphthalic, etc., acids; the saturated monohydric alcohol esters, e. g., the methyl. ethyl, propyl, isopropyl. butyl, sec-butyl, amyl, etc.. esters of unsaturated aliphatic monobasic and polybasic acids, illustrative examples of which appear above; vinyl cyclic compounds (including monovinyi aromatic hydrocarbons), e. g.. styrene, the various halogenostyrenes, alkylstyrenes, cyanostyrenes, ete., vinylnaphthalene, vinylcyclohexane, vinyl furane, vinyl pyridine, vinyldibenzofuran, divinyl benzene, allyl benzene, diallyl benzene, N-vinyl carbazole, the various alpha-substituted styrenes and alpha-substituted ring-substituted styrenes, e. g., alpha-methyl styrene, alpha-methyl-para-methyl styrene, etc: unsaturated ethers. e. g.. ethyl vinyl ether, diallyl ether, ethyl methallyl ether, etc.; unsaturated ketones, e. g., methyl vinyl ketone, methyl allyl ketone, etc.; methylene malonic esters, e. g., methylene methyl malonate, etc.; and unsaturated polyhydric alcohol (e. g., butenediol, butyndiol, etc.) esters of saturated and unsaturated, aliphatic and aromatic, monobasic and polybasic acids, illustrative examples of which appear above. Other examples of monomers which may be copolymerized with acrylonitrile in proportions such as hereinbefore indicated to yield copolymeric acrylonitrile compositions which may be used as flatting agents in filmforming liquid materials are given, for instance, in the copending application of John G. Erickson and Walter M. Thomas, Serial No. 34,143, filed June 19, 1948, and in the copending application of Edward L. Kropa, Serial No. 700,833. filed October 2, 1946 now Patent 2,510,503. which is mentioned in the aforementioned Erickson et 'al. application. In all cases the acrylonitriie copolymer employed as a iiatting agent is one which is insoluble or substantially insoluble in the liquid component or vehicle of the film-forming liquid.

In the preparation of copolymeric acrylonitriles, the proportions of monomers in the polymerizable mixture may be varied as desired or as may be required in order to obtain a polymerization product containing in the polymer molecules an average of at least 85% by weight of acrylonitrile. Thus, when the polymerization rate of the monomers present in the polymerizable mixture is substantially the same, the proportions may be, for example, from, by weight, about 85% to about 99% of acrylonitrile to from about 15% to about 1% of the other comonomer. When the polymerizable mixture contains, in addition to the acrylonitrile, a monomer such, for example, as vinyl chloride, allyl alcohol. etc., which polymerizes at a rate diflerent from that of acrylonitrile, then it may be necessary to sub- Ject to polymerization conditions a mixture in which the acrylonitriie constitutes as little as, for

' instance, 50 or 60% by weight thereof in order to obtain a olymerization product containing in the eopolymer molecules an average of at least 85% by weight of acrylonitrile.

Any suitable method of polymerizing the monomeric acrylonitriie or mixture of monomers may be employed. One suitable method comprises polymerizing the monomer or mixture of monomers in an aqueous emulsion using a suitable polymerization catalyst, e. g., ammonium persulfate. Other polymerization methods, however, also may be used, e. g., methods such as those described in Bauer et ai. Patent No. 2,160,054. The polymeric and copolymeric acrylonitriles employed in practicing our invention generally have a molecular weight of at least 10,000, more particularly within the range of 15,000 to 300,000 or higher, and advantageously the molecular weight is of the order of 20,000 or 25,000 to 140,000 or 150,000, as calculated from viscosity measurements by the Staudinger equa tion (reference: U. S. Patent No. 2,404,713).

The polymeric and copolymeric acrylonitriie ilatting agents hereinbefore described may be used as adjuvants in oleoresinous varnishes or in any other liquid film-forming material, e. g., in liquid coating compositions (paints, varnishes, lacquers, enamels, etc.) wherein the film-forming base includes a cellulose derivative (e. g., nitrocellulose, water-insoluble cellulose others such. for instance, as ethyl cellulose, benzyl cellulose, etc., cellulose esters such, for example, as cellulose acetate, cellulose propionate, cellulose butyrate, cellulose acetopropionate. cellulose acetobutyrate, etc.); a synthetic resin, for instance a vinyl resin such as polyvinyl chloride. polyvinyl acetate, etc., an alkyd resin (e. g., a rosin-modified glyceryl phthalate resin, an oilacid modified glyceryl phthalate resin. etc.), an aminoplast resin (e. g., an alkylated ureaformaldehyde resin, an alkylated melamineformaldehyde resin, etc), an oil-soluble phenoplast resin (e. g., a rosin-modified phenolformaldehyde resin); a silicone resin; a drying or semi-drying oil or mixture thereof; a natural gum or resin (e. g., gum batu, gum damar, gum copal, gum kauri, gum karaya, gum manila, rosin,

"shellac, etc); ester gums; and other film-forniing bases used in the manufacture of paints, varnishes. lacquers, enamels and other liquid aim-forming or coating compositions, as well as homogeneous mixtures or blends of diilerent, compatible, film-forming bases such as those just mentioned by way of example, for instance. a

blend of nitrocellulose and an alkyd resin compatibie therewith, a blend of an aminoplast resin (e. g., a butylated urea-formaldehyde or melamine-formaldehyde resin) and an alkyd resin compatible therewith, etc. Other and more specific examples of film-forming bases and of liquid iim-i'orming materials produced therefrom are given in the aforementioned Laus. Miles, Healy, Harford and Auer patents, any of the liquid coating compositions therein described being adapted for use in practicing the present invention by omitting all or a substantial part of the flatting agent employed or suggested by the patentee and using in its place an acrylonitriie polymerization product oi the kind hereinbefore more fully identified. Any of the volatile solvents and other thinners used in the preparation of coating compositions, examples of which are given in the aforementioned patents and in the examples which follow may be used in the flat liquid compositions of our invention.

In producing the flat liquid coating compositions of the present invention the acrylonitriie polymerization roduct in finely divided or ground state is incorporated into the liquid film-forming material (e. g., a solution of a film-forming base dissolved in a volatile organic solvent) .by any suitable method, such as any of those now commonly employed for incorporating other flatting agents into liquid coating compositions. For example, the flnely divided polymeric or copolymeric acrylonitriie may be mixed and .ground with other components of the coating compositlon in the proportion in which it is desired that the flatting agent be present in the finished coating composition; or, a concentrated paste containing the flatting agent may first be prepared by grinding or mixing the acrylonitriie polymerization product with a portion of the total liquid vehicle content of the coating composition and/ or a portion of the solvent or thinner component of the coating composition, and then diluting the paste with the remainder of the liquid vehicle and/or solvent or thinner. Pebble mills, roller mills or any other suitable equipment may be employed in grinding or otherwise incorporating the flatting agent with or into the liquid coating composition or in forming a homogeneous blend or admixture of the same with other components of the composition. If the acrylonitriie polymerization product has not initially been separately ground to a particle size of 325 mesh (U. S. Standard Sieve Series) or finer prior to its incorporation into the liquid coating composition, it is usually ground at least to this degree of lineness, and generally to even a liner particle size. e. g., 50 to 150 mlllimicrons during its incorporation into the liquid film-forming material or while being ground with components thereof.

From the foregoing it will be seen that a specific embodiment of our invention comprises a flatting composition which can be added to a film-forming liquid material, numerous examples of which have been given hereinbei'ore. This fiatting composition, which is capable of imparting a fiat finish to a film obtained from the resultin iiatted composition, comprises a homogeneous mixture or blend of ingredients comprising (i) a ground acrylonitriie polymerization product containing at least by weight of combined acrylonitrile, e. g., polymeric acrylonitrile, and (2) a liquid vehicle. e. g., an oil, a liquid rosin.

etc.. which is compatible with the liquid component (solvent or thinner) oi the said filmi'orming liquid material, the acrylonltrile polymerization product oi (1) being substantially insoluble in the said liquid vehicle and liquid component.

The amount of acrylonitrile polymerization product which i incorporated into the fiat liquid coating compositions of our invention may be varied as desired or as conditions may require. depending, for example, upon the particular polymeric or copolymeric acrylonitrile employed. the degree of flatness desired in the dried or baked film, the other components of the liquid film-forming material, etc. Ordinarily, however,'when used as a dulling'agent only, the amount of acrylonitrile polymerization product will be from about 0.2 to about 5% by weight of the finished liquid coating composition, but in some cases, as for example when the acrylonitrile polymerization product is to be used both as a dulling agent and as the sole pigment because of its intrinsic properties, it may constitute as much as 20 or 25% by weight of the finished coating composition.

In order'that those skilled in the art better may understand how the present invention may be carried into eflect, the following examples are given by way of illustration and not by way of limitation. All parts and percentages are by weight.

Example 1 Parts 56 sec. nitrocellulose (dry weight) 100 Alkyd resin, specifically a glyceryl phthalate resin modified with fatty acids comprising mainly lauric, oleic, palmitic and linoleic acids 100 Polyacrylonitrile 7 Dibutyl phthalate l5 Blown castor oil 15 Butyl alcohol 120 Butyl acetate 240 Ethyl acetate 360 Xylol 480 Example 2 A white pigmented enamel was prepared by grinding together the following ingredients for 18 hours in a pebble mill:

Parts Alkyd resin solution 150.0 Titanium dioxide 85.0 Polyacrylonitrile 15.0 Mineral spirits (Varsol No. 1) 50.0 Cobalt naphthenate Seem) calcium naphthenate See (b) Solution of 35% mineral spirits and 65% of ataerythrltig phthalate polyester modified with fatty zcids of soya n oil.

I g 0.04% as metallic cobalt based on the alkyd resin an coast a metallic calcium time on the alkyd resin Example 3 .Parts solution of butylated urea-formaldehyde resin (55% resin solids, 45% of a 50-50 solvent mixture of butanol and xylene) 100.0 Solution oi a glyceryl phthalate resin modified with rosin and linseed oil acids (50% resin solids, 50% xylene) 100.0 Catalyst (solution of 40% methyl acid pyrophosphate dissolved in a solvent comprising mainly butanol) 5.0 Xylene 20.0 Butanol 20.0 Flatting agent 7.5

Finely divided polyacrylonitrlle and other fiatting agents, specifically silica gel, metallic stearates, and an aluminum soap of a maleic acid-rosin adduct, were ground into the above composition, which is a low-bake furniture finish, using regular pebble mill technique. Aiter grinding for 24 hours, they were adjusted to give a gloss rating of on the 60 Gardner gloseometer. Unlike the metallic stearates, specifically aluminum stearate, and the aluminum soap or an adduct 01 maleic acid and resin. which prevented curing of aims of the finish, the polyacrylonitrlle did not inhibit or prevent curing. Furthermore, unlike the finish containing silica gel as a flatting agent, which finish had very poor water resistance, the iinish containing the polyacrylonitrile had excellent water resistance.

Example 4 To a base gloss lacquer composed of 200 parts or the same alkyd resin used in Example 1 and parts or A second nitrocellulose dissolved in a solvent combination of 10% butyl alcohol, 20% butyl acetate, 30% ethyl acetate and 40% toluene was added 10 parts of polyacrylonitrile. Bimilar compositions were prepared using the same amount of silica gel and aluminum stearate. The three compositions'were separately ground by the usual pebble mill technique. After grinding for 24 hours the lacquers were reduced to spraying consistency by adding the above solvent combination and were adjusted to a gloss reading oi 79-81 on the 60 Gardner glossometer by adding further quantities of the base gloss lacquer. The percentages (based on the total non-volatile content of the lacquers) of each fiatting agent necessary to obtain this gloss range are as follows:

Percent Polyacrylonltrile 1.15 Aluminum stearate 2.31 Silica gel 1.12

The amount of polyacrylonitrile required to give the same fiatting eiiect is approximately the same as that required with silica gel, but the former has the advantage over the latter, among other benefits, in that it provides a dried film having greatly im roved resistance to water.

use?" The netting eflect oi the polyacrylonitrile is approximately twice that 01' the aluminum stearate.

The foregoing lacquers were maintained at about 180 F. for 96 hours in order to observe their tendencies toward gelation, settling and agglomeration. In the lacquer containing the silica gel, the silica gel settled to a soft sediment which had a tendency to flocculate upon stirring. In the lacquer which contained the aluminum stearate, the aluminum stearate dissolved and lost all its fiatting effect. In marked contrast, the polyacrylonitrile in the lacquer which contained this flatting agent settled to a sort sediment which dispersed readily upon stirring. Furthermore, the polyacrylonitrile showed no flocculation tendencies on stirring and no evidence of dissolution. These results show that a liquid coating composition containing an acrylonitrile polymerization product is not detrimentally aifected by prolonged heating at an elevated temperature, specifically about 130 F. The liquid coatin compositions of our invention. therefore. may be ex osed to elevated temperatures of the order 01' 100 F. to 150 F. for a rolon ed period, such as may be encountered during shi ment in hot box cars or during Storage in hot warehouses, without afl'ecting the polyacrvlonitrlle fiatting a ent or wit out detrimentallv ail'ect ng the coating composition or causing dimculty in its subse ent use.

The flat liquid coating compositions of this invention may be used wherever it isdeslred to obtain a dull or flat finish on articles, for instance in coating floors. furnit re. mi itary equipment, aircraft. etc. The acrylonitrile olymerization products may be used as fiatting a ents in both c ear and pigmented varnishes. They may be used alone or in coniunction with conventional fiatting agents. such as metall c stearates. silica el, etc.. in ord r to fortify the latter. They also may be employed in coating com ositions as carriers for dves or other colorin: matter. Alternativelv, the acrvlonitrile polymerization products may be used in coating comosit ons along with other colored pi ments.

C rtain of the acrvlonitriie po ymerization products also may be em loyed in the fiattin o1 artificial fibers s ch. for exam le, as t e various rayon and other fibers made by wet spinning processes. Thus, while nolyacrylonitrile is insoluble in all the common organic liquids used in film-forming a plications, the polymer is swollen by a number of the powerful solvents used in the fiber-spinning industry. Hence. in order to overcome any partial swelling or solution of the acrylonltrile polymerization product in such spec alized applications, conolymers of acrylonitrile advantageously may be employed, more particularly those in which a minor amount of a copolymerlzable material capable of yielding a cross-linked, substantially iniusible copolymer is used in the preparation of the copolymer. Examples or such copolymerizable materials are di vinyl benzene. diallyl phthalate, diallyl fumarate, glycol i'umarate polyesters, etc.

We claim:

1. A flat liquid coating composition including (1) a liquid comprising a film-forming base and (2) a finely divided acrylonitrile polymerization product containing at least 85% by weight thereof 01 combined acrylonitrile, said filmi'orming base being difi'erent from said acrylonitrile polymerization product of (2), and the said acryionitrlle polymerization product being 10 substantially insoluble in the said flat liquid ecsting composition.

2. A flat liquid coating composition including (1) a liquid comprising a film-forming base and (2) a fiatting agent comprising finely divided polymeric acrylonitrile, said polymeric acrylonitrile constituting from about 0.2% to about 25% by weight of the said liquid coating composition and being substantially insoluble therein, and said film-forming base being diilerent from said polymeric acrylonitrile.

3. A flat liquid coating composition as in claim 2 wherein the polymeric acrylonitrile has a. molecular weight oi at least 10,000.

4. A fiat liquid coating composition comprising 1) a clear varnish including a liquid containing a film-forming base and (2) a flatting agent comprising finely divided polymeric acrylonitrile, said polymeric acrylonitrile constituting from about 0.2% to about 25% by weight of the said liquid coating composition and being substantially insoluble therein, and said film-forming base being different from said polymeric acrylonitrile.

5. A flat liquid coating composition comprising nitrocellulose, a solvent therefor and a flatting agent comprising finely divided polymeric acrylonitrile dispersed throughout the said coating composition, said polymeric acrylonitrile constituting from about 0.2% to about 25% by weight of the said liquid coating composition and being substantially insoluble therein.

6. A flat liquid coating composition comprising an alkyd resin and a flatting agent comprising finely divided polymeric acrylonitrile dispersed throughout the said coating composition. said polymeric acrylonitrile constituting from about 0.2% to about 25% by weight of the said liquid coating composition and being substantially insoluble therein.

7. A flat liquid coating composition comprising (1) nitrocellulose, (2) an alnd resin compatible with the said nitrocellulose, (3) a thinner and i) finely divided polymeric acrylonitrile as a flatting agent, said polymeric acrylonitrile constituting from about 0.2% to about 5% by weight oi the said liquid coating composition and being substantially insoluble therein.

8. A flat liquid coating composition comprising an aminoplast resin and a fiatting agent comprising finely divided polymeric acrylonitrile dispersed throughout the said composition, said polymeric acrylonitrile constituting from about 0.2% to about 25% by weight of the said liquid coating composition and being substantially insoluble therein.

9. A flat liquid coating composition as in claim 8 wherein the aminoplast resin is a urea-formaldehyde resin.

10. A flat liquid coating composition comprising (1) an aminoplast resin, (2) an alkyd resin compatible with the resin of (1), (8) a thinner and (4) finely divided polymeric acrylonitrile as a netting agent, said polymeric acrylonitrile constituting from about 0.2% to about 25 by weight of the said liquid coating composition and being substantially insoluble therein.

11. A flatting composition in concentrated form and which is capable of dilution to iorm a flat liquid coating composition, said fiatting composition in concentrated form comprising (1) a liquid containing a film-forming base and (2) a finely divided acrylonitrile polymerization product containing at least by weight of combined acrylonitrile, said film-forming base being diflerent from eaid acrylonitrile polymerization product 01' (2). and the said acrylonitrile polymerization product being substantially insoluble in the said flatting composition in concentrated form and in the flat liquid coating composition produced from said concentrated netting composition 12. A flatting composition as in claim 11 wherein the acrylonitrile polymerization product is polymeric acrylonitril 13. A flat liquid coating composition as in claim 1 wherein the particle size of the acrylonitrile polymerization product is at least 325 mesh.

14. A flat liquid coating composition as in claim The ioiiowin: re!

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1. A FLAT LIQUID COATING COMPOSITION INCLUDING (1) A LIQUID COMPRISING A FILM-FORMING BASE AND (2) A FINELY DIVIDED ACRYLONITRILE POLYMERIZATION PRODUCT CONTAINING AT LEAST 85% BY WEIGHT THEREOF OF COMBINED ACRYLONITRILE, SAID FILMFORMING BASE BEING DIFFERENT FROM SAID ACRYLONITRILE POLYMERIZATION PRODUCT OF (2), AND THE SAID ACRYLONITRILE POLYMERIZATION PRODUCT BEING SUBSTANTIALLY INSOLUBLE IN THE SAID FLAT LIQUID COATING COMPOSITION. 